U.S. patent number 11,179,959 [Application Number 16/362,330] was granted by the patent office on 2021-11-23 for security element with a metallized structured surface.
This patent grant is currently assigned to 3M Innovative Properties Company. The grantee listed for this patent is 3M INNOVATIVE PROPERTIES COMPANY. Invention is credited to Douglas S. Dunn, William Blake Kolb, Ta-Hua Yu.
United States Patent |
11,179,959 |
Yu , et al. |
November 23, 2021 |
Security element with a metallized structured surface
Abstract
A security element, including: a substrate having a first
structured major surface and a second structured major surface; and
a first metal layer coated on the first structured major surface,
wherein the transparency of the first metal layer is between 10%
and 90%; and a second metal layer coated on the second structured
major surface.
Inventors: |
Yu; Ta-Hua (Woodbury, MN),
Kolb; William Blake (Stillwater, MN), Dunn; Douglas S.
(Woodbury, MN) |
Applicant: |
Name |
City |
State |
Country |
Type |
3M INNOVATIVE PROPERTIES COMPANY |
St. Paul |
MN |
US |
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Assignee: |
3M Innovative Properties
Company (St. Paul, MN)
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Family
ID: |
1000005952857 |
Appl.
No.: |
16/362,330 |
Filed: |
March 22, 2019 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20190299700 A1 |
Oct 3, 2019 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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62648555 |
Mar 27, 2018 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B42D
25/324 (20141001); B42D 25/328 (20141001); B42D
25/351 (20141001); B42D 25/373 (20141001) |
Current International
Class: |
B42D
25/328 (20140101); B42D 25/47 (20140101); B42D
25/351 (20140101); B42D 25/324 (20140101); B42D
25/373 (20140101) |
Field of
Search: |
;283/67,70,72,74,94,98 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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1387231 |
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1452728 |
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1871531 |
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101368352 |
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Feb 2009 |
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CN |
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106313934 |
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Jan 2017 |
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CN |
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1271627 |
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Jan 2003 |
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EP |
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2192428 |
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EP |
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WO 9740464 |
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Oct 1997 |
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WO |
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WO 01/75517 |
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WO |
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WO 03053713 |
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WO |
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WO 2017/003870 |
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Jan 2017 |
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WO |
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Other References
Extended Search Report, EP19164937.5, dated Sep. 17, 2019, 3 pages.
cited by applicant.
|
Primary Examiner: Lewis; Justin V
Claims
What is claimed is:
1. A security element, comprising: a substrate having a first
structured major surface and a second structured major surface; and
a first metal layer coated on the first structured major surface,
wherein a transparency of the first metal layer is between 10% and
90%; wherein the first metal layer is a continuous monolayer; a
second metal layer coated on the second structured major surface;
wherein the first or second metal layer is not patterned; wherein
the first or second structured major surface comprises a plurality
of features; and wherein the plurality of features in the first or
second structured major surface are randomly arrayed features.
2. The security element of claim 1, wherein a transparency of the
second metal layer is less than 50%.
3. The security element of claim 1, wherein the second metal layer
is a continuous monolayer.
4. The security element of claim 1, wherein the plurality of
features are nanoscale features.
5. The security element of claim 1, wherein the randomly arrayed
features are randomly arrayed nanoscale features.
6. The security element of claim 1, wherein the plurality of
features comprise microscale features and nanoscale features.
7. The security element of claim 6, wherein the nanoscale features
are formed on the microscale features.
8. The security element of claim 1, wherein the plurality of
features comprise ordered microscale features and randomly arrayed
nanoscale features.
9. The security element of claim 1, further comprising a
binder.
10. The security element of claim 1, wherein the first or second
metal layer comprises individual metals, multilayer metals, two or
more metals as mixtures, inter-metallics or alloys, semi-metals or
metalloids, metal oxides, metal and mixed metal oxides, metal and
mixed metal fluorides, metal and mixed metal nitrides, metal and
mixed metal carbides, metal and mixed metal carbonitrides, metal
and mixed metal oxynitrides, metal and mixed metal borides, metal
and mixed metal oxy borides, metal and mixed metal silicides, and
combinations thereof.
11. The security element of claim 10, wherein the individual metals
are selected from the group of Au, Ag, Pt, Cu, Al and Cr.
12. The security element of claim 1, wherein the security element
is an anti-counterfeit label.
13. A method, comprising: providing the security element of claim
1; and obtaining a reflective diffraction pattern from the security
element.
14. The method of claim 13, further comprising determining an
authenticity based on the reflective diffraction pattern.
15. The method of claim 14, wherein the diffraction pattern can be
observed visually, or determined with a visible light detection
apparatus.
16. The method of claim 13, wherein obtaining the reflective
diffraction pattern comprises applying a laser to the security
element.
Description
BACKGROUND
Product counterfeiting has been on the rise in many industries. For
protection, valuable articles, such as branded articles, are often
provided with security elements that permit the authenticity of the
articles to be verified, and that simultaneously serve as
protection against unauthorized reproduction. Security elements
play a special role in safeguarding authenticity, as these cannot
be reproduced even with the most modern copiers. However, there is
a need for better security element.
SUMMARY
Thus, in one aspect, the present disclosure provides a security
element, comprising: a substrate having a first structured major
surface and a second structured major surface; and a first metal
layer coated on the first structured major surface, wherein the
transparency of the first metal layer is between 10% and 90%; and a
second metal layer coated on the second structured major
surface.
In another aspect, the present disclosure provides a method,
comprising: providing the security element of current application;
and obtaining a reflective diffraction pattern from the security
element.
Various aspects and advantages of exemplary embodiments of the
present disclosure have been summarized. The above Summary is not
intended to describe each illustrated embodiment or every
implementation of the present disclosure. Further features and
advantages are disclosed in the embodiments that follow. The
Drawings and the Detailed Description that follow more particularly
exemplify certain embodiments using the principles disclosed
herein.
BRIEF DESCRIPTION OF THE DRAWINGS
The disclosure may be more completely understood in consideration
of the following detailed description of various embodiments of the
disclosure in connection with the accompanying figures, in
which:
FIG. 1 is a schematic side view of one embodiment of security
element.
While the above-identified drawings, which may not be drawn to
scale, set forth various embodiments of the present disclosure,
other embodiments are also contemplated, as noted in the Detailed
Description. In all cases, this disclosure describes the presently
disclosed invention by way of representation of exemplary
embodiments and not by express limitations. It should be understood
that numerous other modifications and embodiments can be devised by
those skilled in the art, which fall within the scope and spirit of
this disclosure.
DETAILED DESCRIPTION
Before any embodiments of the present disclosure are explained in
detail, it is understood that the invention is not limited in its
application to the details of use, construction, and the
arrangement of components set forth in the following description.
The invention is capable of other embodiments and of being
practiced or of being carried out in various ways that will become
apparent to a person of ordinary skill in the art upon reading the
present disclosure. Also, it is understood that the phraseology and
terminology used herein is for the purpose of description and
should not be regarded as limiting. The use of "including,"
"comprising," or "having" and variations thereof herein is meant to
encompass the items listed thereafter and equivalents thereof as
well as additional items. It is understood that other embodiments
may be utilized and structural or logical changes may be made
without departing from the scope of the present disclosure.
As used in this Specification, the recitation of numerical ranges
by endpoints includes all numbers subsumed within that range (e.g.
1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.8, 4, and 5, and the
like).
Light transmission characteristic of a security element is
described as transparency. The transparency of a security element
is normally measured by its total transmittance. Total
transmittance is the ratio of transmitted light to the incident
light. There are two influencing factors; reflection and
absorption. For example: Incident
light=100%-(Absorption=-1%+Reflection=-5%)=Total Transmittance=94%.
The total transmittance of a regular glass slide is about 92%.
Metallization can reduce total transmittance significantly which is
mainly due to absorption behavior of metal coating and dependent on
metal coating thickness. For example, the total transmittance of a
glass slide coated with 100 nm silver is less than 1%. The total
transmittance of a glass slide coated with 10 nm silver is about
69%.
Unless otherwise indicated, all numbers expressing quantities or
ingredients, measurement of properties and so forth used in the
Specification and embodiments are to be understood as being
modified in all instances by the term "about." Accordingly, unless
indicated to the contrary, the numerical parameters set forth in
the foregoing specification and attached listing of embodiments can
vary depending upon the desired properties sought to be obtained by
those skilled in the art utilizing the teachings of the present
disclosure. At the very least, and not as an attempt to limit the
application of the doctrine of equivalents to the scope of the
claimed embodiments, each numerical parameter should at least be
construed in light of the number of reported significant digits and
by applying ordinary rounding techniques.
There is an increased need for security elements to permit the
authenticity of the articles to be verified, for example, branded
articles. The present application provides a security element to,
which can be used to verify the authenticity of the articles.
FIG. 1 is a schematic side view of one embodiment of security
element 100. The security element 100 includes a substrate 120. The
substrate 120 includes a first structured major surface 122 and a
second structured major surface 126. The first structured major
surface 122 and a second structured major surface 126 can include a
plurality of features 123. The security element 100 may further
include a first metal layer 130 on the first structured major
surface 122 of the substrate 120. The security element 100 may
further include a second metal layer 150 on the second structured
major surface 126 of the substrate 120. In the embodiment of FIG.
1, the first or second metal layer can conform to the shape of
features of the first or second structured major surface.
Alternatively, in other embodiments, the first or second metal
layer can have a first major surface to conform to the shape of
features and a second flat major surface. In some embodiments, the
transparency of the first metal layer can be between 10% and 90%,
between 20% and 90%, between 30% and 90%, between 40% and 90%, or
between 50% and 90%. In some embodiments, the transparency of the
second metal layer can be less than 50%, less than 40%, less than
30%, less than 20%, less than 10%, or less than 5%. The security
element 100 may further include an optional binder. In some
embodiments, the first or second metal layer can be a continuous
monolayer. In some embodiments, the first or second metal layer can
be not patterned.
In some embodiments, the plurality of features 123 can be a
plurality of microscale features. In some embodiments, the
plurality of features 123 can be a plurality of nanoscale features.
In some embodiments, the plurality of features 123 can be randomly
arrayed features. In some embodiments, the randomly arrayed
features can be randomly arrayed nanoscale features. In some
embodiments, the plurality of microscale features or nanoscale
features may be randomly arrayed features. In some embodiments, the
plurality of features 123 can be orderly arrayed features. In some
embodiments, the plurality of microscale features or nanoscale
features may be ordered features. In some embodiments that the
first or second structured major surface include a plurality of
both microscale features and nanoscale features, at least part of
the nanoscale features may be formed on the microscale features. In
some embodiments, the first or second structured major surface may
include both ordered microscale features and randomly arrayed
nanoscale features. In some embodiments, microscale features or
nanoscale features may be microreplicated features. In some
embodiments, microscale features or nanoscale features may be
linear prisms.
In some embodiments, the nanoscale features have a high aspect
ratio (the ratio of height to width). In some embodiments, aspect
ratio (the ratio of height to width) of the nanoscale features is
1:1, 2:1, 4:1, 5:1, 8:1, 10:1, 50:1, 100:1, or 200:1. In some
embodiments, aspect ratio (the ratio of height to width) of the
nanoscale features can be more than 1:1, 2:1, 4:1, 5:1, 8:1, 10:1,
50:1, 100:1, or 200:1. Nanoscale features can be such as, for
example, nano-pillars or nano-columns, or continuous nano-walls
comprising nano-pillars or nano-columns. In some embodiments, the
nanoscale features have steep side walls that are substantially
perpendicular to the substrate. In some embodiments, the majority
of the nanoscale features can be capped with mask material.
In the embodiment as shown in FIG. 1, the features are linear
prismatic features. Each linear prismatic features 123 includes an
apex angle 132 and a height 154 measured from a common reference
plane such as, for example, major plane surface 160, In some cases,
such as when it is desirable to reduce optical coupling, or
wet-out, some of the linear prismatic features are shorter and some
of the linear prismatic features are taller. Apex or dihedral angle
132 can have any value that may be desirable in an application. For
example, in some cases, apex angle 132 can be in a range from about
70 degrees to about 110 degrees, or from about 80 degrees to about
100 degrees, or from about 85 degrees to about 95 degrees. In some
cases, microstructures 123 have equal apex angles which can, for
example, be in a range from about 88 or 89 degrees to about 92 or
91 degrees, such as 90 degrees.
Substrate may include any of a wide variety of non-polymeric
materials, such as glass, or various thermoplastic and crosslinked
polymeric materials, such as polyethylene terephthalate (PET),
polyethylene naphthalate (PEN), (e.g. bisphenol A) polycarbonate,
cellulose acetate, poly(methyl methacrylate), and polyolefins such
as biaxially oriented polypropylene, cyclic olefin polymer (COP),
and cyclic olefin copolymer (COP) which are commonly used in
various optical devices. In some embodiments, the substrate may be
removable substrate.
The first or second metal layer can be formed from a variety of
materials including, for example, individual metals, multilayer
metals, two or more metals as mixtures, inter-metallics or alloys,
semi-metals or metalloids, metal oxides, metal and mixed metal
oxides, metal and mixed metal fluorides, metal and mixed metal
nitrides, metal and mixed metal carbides, metal and mixed metal
carbonitrides, metal and mixed metal oxynitrides, metal and mixed
metal borides, metal and mixed metal oxy borides, metal and mixed
metal silicides, diamond-like carbon, diamond-like glass, graphene,
and combinations thereof. Exemplary individual metals can include
Au, Ag, Pt, Cu, Al and Cr. Exemplary metal oxides include silicon
oxides such as silica, aluminum oxides such as alumina, titanium
oxides such as titania, indium oxides, tin oxides, indium tin oxide
(ITO), tantalum oxide, zirconium oxide, niobium oxide, and
combinations thereof. Other exemplary materials include boron
carbide, tungsten carbide, silicon carbide, aluminum nitride,
silicon nitride, boron nitride, aluminum oxynitride, silicon
oxynitride, boron oxynitride, zirconium oxyboride, titanium
oxyboride, and combinations thereof.
The binder can be an organic binder. Examples of suitable organic
binders that are useful in abrasive composites include phenolics,
aminoplasts, urethanes, epoxies, acrylics, cyanates, isocyanurates,
glue, and combinations thereof. In some embodiments, the binder can
include acrylic acid polymer, methyl acrylate, methyl methacrylate
and acrylic acid 2-ethyl hexyl fat, initiator comprises
benzophenone, related aminobenzophenones di ethylaluminium,
colorless crystal violet, toluene sulfonic acid-hydrate and diamond
GH malachite green, 9G comprises a photopolymerizable monomer,
APG-400 and the BPE-500, the solvent comprises methyl ethyl
ketone.
The substrate 120 can have any index of refraction that may be
desirable in an application. For example, in some cases, the index
of refraction of the substrate is in a range from about 1.4 to
about 1.8, or from about 1.5 to about 1.8, or from about 1.5 to
about 1.7. In some cases, the index of refraction of the substrate
is not less than about 1.5, or not less than about 1.55, or not
less than about 1.6, or not less than about 1.65, or not less than
about 1.7.
The security element of current application can be used as an
identification feature for security and authentication
applications, for example, an anti-counterfeit label, an
authentication tape, or an identification feature for document
authentication, license plate, driver license, passport and
currency, advanced food, pharmaceutical and healthcare packaging.
The security element can display a unique reflective diffraction
pattern, for example, sharp spectral lines and/or dots. A method to
verify the authenticity of an article is describe. The method can
include providing the security element of current application and
obtaining a reflective diffraction pattern from the security
element. The method can further include determining the
authenticity based on the reflective diffraction pattern, for
example by the user's eye, or visible light detection apparatus. In
some embodiments, the reflective diffraction pattern can be
obtained by applying a laser to the security element.
The following embodiments are intended to be illustrative of the
present disclosure and not limiting.
EMBODIMENTS
Embodiment 1 is a security element, comprising: a substrate having
a first structured major surface and a second structured major
surface; and a first metal layer coated on the first structured
major surface, wherein the transparency of the first metal layer is
between 10% and 90%; and a second metal layer coated on the second
structured major surface.
Embodiment 2 is the security element of embodiment wherein the
transparency of the second metal layer is less than 50%.
Embodiment 3 is the security element of any one of embodiments 1 to
2, wherein the first or second metal layer is a continuous
monolayer.
Embodiment 4 is the security element of any one of embodiments 1 to
3, wherein the first or second metal layer is not patterned.
Embodiment 5 is the security element of any one of embodiments 1 to
4, wherein the first or second structured major surface comprises a
plurality of features.
Embodiment 6 is the security element of embodiment 5, wherein the
plurality of features are nanoscale features.
Embodiment 7 is the security element of embodiment 5, wherein the
plurality of features are randomly arrayed features.
Embodiment 8 is the security element of embodiment 7, wherein the
randomly arrayed features are randomly arrayed nanoscale
features.
Embodiment 9 is the security element of embodiment 5, wherein the
plurality of features are orderly arrayed features.
Embodiment 10 is the security element of embodiment 5, wherein the
plurality of features comprise microscale features and nanoscale
features.
Embodiment 11 is the security element of embodiment 5, wherein the
plurality of features comprise ordered microscale features and
randomly arrayed nanoscale features.
Embodiment 12 is the security element of embodiments 10-11, wherein
the nanoscale features are formed on the microscale features.
Embodiment 13 is the security element of embodiments 1-12, further
comprising a binder.
Embodiment 14 is the security element of embodiments 1-13, wherein
the first or second metal layer comprises individual metals,
multilayer metals, two or more metals as mixtures, inter-metallics
or alloys, semi-metals or metalloids, metal oxides, metal and mixed
metal oxides, metal and mixed metal fluorides, metal and mixed
metal nitrides, metal and mixed metal carbides, metal and mixed
metal carbonitrides, metal and mixed metal oxynitrides, metal and
mixed metal borides, metal and mixed metal oxy borides, metal and
mixed metal silicides, diamond-like carbon, diamond-like glass,
graphene, and combinations thereof.
Embodiment 15 is the security element of embodiment 14, wherein the
individual metals are selected from the group of Au, Ag, Pt, Cu, Al
and Cr.
Embodiment 16 is the security element of embodiments 1-15, wherein
the security element is an anti-counterfeit label.
Embodiment 17 is a method, comprising: providing the security
element of embodiments 1-16; and obtaining a reflective diffraction
pattern from the security element.
Embodiment 18 is the method of embodiment 17, further comprising
determining the authenticity based on the reflective diffraction
pattern.
Embodiment 19 is the method of embodiment 18, wherein determining
the authenticity comprises determine the pattern by the user's eye,
or visible light detection apparatus.
Embodiment 20 is the method of embodiments 1-19, wherein obtaining
the reflective diffraction pattern comprises applying a laser to
the security element.
EXAMPLES
The following Examples are merely for illustrative purposes and are
not meant to be overly limiting on the scope of the appended
claims. Notwithstanding that the numerical ranges and parameters
setting forth the broad scope of the present disclosure are
approximations, the numerical values set forth in the specific
examples are reported as precisely as possible. Any numerical
value, however, inherently contains certain errors necessarily
resulting from the standard deviation found in their respective
testing measurements. At the very least, and not as an attempt to
limit the application of the doctrine of equivalents to the scope
of the claims, each numerical parameter should at least be
construed in light of the number of reported significant digits and
by applying ordinary rounding techniques.
Unless otherwise noted, all parts, percentages, ratios, and the
like in the Examples and the rest of the specification are provided
on the basis of weight. Solvents and other reagents used may be
obtained from Sigma-Aldrich Chemical Company (Milwaukee, Wis.)
unless otherwise noted.
Test Methods:
The following test methods were used to characterize sputtered
silver coating and assembled articles.
Method 1: Ceramic Coating Thickness
The ceramic coating thickness was measured indirectly using a Veeco
Dektak profilometer (Veeco Instruments, Plainview, N.Y.). Kapton
tape was applied on and partially covering the surface of a glass
slide. After coating the ceramic on the covered and uncovered
surface of the glass slide using PVD (Sputtering), the tape was
removed from the glass slide, and the coating thickness was
determined from the step change observed when scanning the stylus
probe of the Veeco Dektak contact profilometer across the coated
and uncoated surface of the glass slide.
Method 2: Reflective Diffraction Pattern
A laser beam from a laser pointer is pointed on the surface of the
article and the reflective diffraction pattern is projected on to a
paper, Post-it, or any substrate that can used as a projection
screen. The distance between the laser point and the surface of the
article can be from couples of centimeter to tens of centimeter.
The angle of the incident laser beam to the surface of the article
can be from 5 degree to 75 degree. The reflective diffraction
patterns can be visualized on the projection screen.
Example 1
A coating of metallic silver was sputtered from a 76.2 mm round
silver target in a batch vacuum sputter coater. 3M.TM. Brightness
Enhancement Film (BEF) was placed on a substrate holder set up
inside a vacuum chamber with a sputtering metal target located at a
height of 228.6 mm above the substrate holder. The micro-prism
surface of the BEF was facing the sputtering target. After the
vacuum chamber was evacuated to 2.times.10.sup.-5 torr base
pressure, argon was admitted inside the chamber and the total
pressure of the vacuum chamber was adjusted to 3 millitorr.
Sputtering was initiated using a DC power supply at a constant
power level of 0.5 kilowatts until the coating thickness reached
100 nm.
Example 2
A coating of metallic silver was sputtered from a 76.2 mm round
silver target in a batch vacuum sputter coater. 3M.TM. Brightness
Enhancement Film (BEF) was placed on a substrate holder set up
inside a vacuum chamber with a sputtering metal target located at a
height of 228.6 mm above the substrate holder. The micro-prism
surface of the BEF was facing the sputtering target. After the
vacuum chamber was evacuated to 2.times.10.sup.-5 torr base
pressure, argon was admitted inside the chamber and the total
pressure of the vacuum chamber was adjusted to 3 millitorr.
Sputtering was initiated using a DC power supply at a constant
power level of 0.5 kilowatts until the coating thickness reached 10
nm.
Example 3
3M Optically Clear Adhesive 8211 was applied onto the metallized
micro-prism surface of the sample from Example 1. The
non-metallized side of the sample from Example 2 was then laminated
onto the adhesive with the long axis of the micro-prisms of the
sample from Example 2 perpendicular to the long axis of the
micro-prism of the sample from Example 1. A composited reflective
diffraction pattern having a dotted radial arc and a dotted
straight line was observed by Test Method #2.
Example 4
A microstructured film comprising spherical microlens arrays was
obtained from MNTech Co. Ltd. (South Korea). This film was placed
on a substrate holder set up inside a vacuum chamber with a
sputtering metal target located at a height of 228.6 mm above the
substrate holder. The spherical microlens arrays of the film were
facing the sputtering target. After the vacuum chamber was
evacuated to 2.times.10.sup.-5 torr base pressure, argon was
admitted inside the chamber and the total pressure of the vacuum
chamber was adjusted to 3 millitorr. Sputtering was initiated using
a DC power supply at a constant power level of 0.5 kilowatts until
the coating thickness reached 10 nm.
Example 5
3M Optically Clear Adhesive 8211 was applied onto the metallized
micro-prism surface of the sample from Example 1. The
non-metallized side of the sample from Example 4 was then laminated
onto the adhesive. A composited reflective diffraction pattern of
multiple dotted radial arcs from the resulted article was observed
by Test Method #2.
All references and publications cited herein are expressly
incorporated herein by reference in their entirety into this
disclosure. Illustrative embodiments of this invention are
discussed and reference has been made to possible variations within
the scope of this invention. For example, features depicted in
connection with one illustrative embodiment may be used in
connection with other embodiments of the invention. These and other
variations and modifications in the invention will be apparent to
those skilled in the art without departing from the scope of the
invention, and it should be understood that this invention is not
limited to the illustrative embodiments set forth herein.
Accordingly, the invention is to be limited only by the claims
provided below and equivalents thereof.
* * * * *